- #1
Jayce
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Homework Statement
In a stage production of Peter Pan, the 60 kg actress playing Peter has to fly in vertically, and to be in time with the music, she must be lowered, starting from rest, a distance of 3.2 m in 2.2 s. Backstage, a smooth surface sloped at 59º supports a counterweight of mass m.
What is the mass of the counterweight that must be used? The pulley is of negligible mass and is frictionless. The acceleration of gravity is 9.81 m/s². Answer in units of kg.
Homework Equations
d = vit + ½at²
acceleration = g*sin(Θ)
Mass = Force/Acceleration
The Attempt at a Solution
d = vit + ½at²
3.2 = ½a(2.2)²
a = 1.322
Using the distance equation and solving for acceleration, the acceleration of Peter would be 1.322 m/s²
F = mass x acceleration
F = 60 kg x 1.322
F = 79.338 N
This is the force of Peter as he falls.
acceleration of weight m = 9.81*sin(59)
= 8.408 m/s²
Mass of m = Force/Acceleration
= 79.338 N / 8.408 m/s²
= 9.435 kg
My final answer was very much incorrect. Is there another formula I was supposed to use?